KR101385785B1 - Methods for congestion control for machine type communication (mtc) devices or low priority devices, and apparatuses using the same - Google Patents

Abstract

A mobile communication device configured for Machine Type Communication (MTC) or configured as a low priority device is provided. In a mobile communication device, a wireless module performs wireless transmission and reception for a service network, and a controller module performs a combined connection procedure or combined routing area update procedure for both packet switched (PS) and circuit switched (CS) domains. And in response to initiating a transmit a connection request message to the service network via the wireless module, and receive a connection deny message with an indication of an extended wait timer from the service network via the wireless module. In addition, the controller module initiates a location registration procedure for the CS domain or enters a sub state in which initiation of the location registration procedure for the CS domain is allowed in response to the access rejection message for the PS domain.

Description

METHODS FOR CONGESTION CONTROL FOR MACHINE TYPE COMMUNICATION (MTC) DEVICES OR LOW PRIORITY DEVICES, AND APPARATUSES USING THE SAME}

Cross-reference to related application

This invention claims the priority of US Provisional Application No. 61 / 425,661, filed December 21, 2010, the entire contents of which are incorporated herein by reference.

Technical field

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to congestion control technology, and more particularly, to a method and apparatus using the same for congestion control for a machine type communication (MTC) device or a low priority device. .

For a long time various machines have been provided to make our lives more convenient in every way. In general, machines nowadays have computing processors and software that will provide us with more functionality-based services. BACKGROUND OF THE INVENTION The development of wireless communications has led to the development of MTC, which enables communication between remote machines to exchange and operate information without human interaction. Especially for critical public infrastructure such as water treatment facilities or bridges, it monitors the operation status of the facility and monitors Global System for Mobile communications (GSM) technology, General Packet Radio Service (GPRS) technology, Enhanced Data rates for Global Evolution (EDGE) technology. , Wideband Code Division Multiple Access (WCDMA) technology, Code Division Multiple Access 2000 (CDMA 2000) technology, Time Division-Synchronous Code Division Multiple Access (TD-SCDMA) technology, Worldwide Interoperability for Microwave Access (WiMAX) technology, Long LTE The MTC sensor may be employed to report the measurement results to the control center via a wireless communication network such as Term Evolution (LTE) technology, LTE-Advanced (LTE-A) technology, and the like.

As an example, LTE technology is taken according to the 3GPP TS 23.060 specification, v10.1.0 (hereafter referred to as TS 23.060 specification) and the 3GPP TS 25.331 specification, v10.1.0 (hereafter referred to as TS 25.331 specification). When too many mobile devices access a Serving GPRS Support Node (SGSN), congestion may occur in the SGSN, ie the Packet-Switched (PS) domain of the service network becomes congested. For PS domain congestion, the SGSN instructs the Radio Network Controller / Base Station Subsystem (RNC / BSS) to deny access requests for the PS domain from any MTC device or low priority device. An extended wait timer is displayed along with the rejection of the connection request. If the connection request is denied, the MTC device or low priority device starts an extended wait timer and does not initiate establishment of a PS connection during the duration of the extended wait timer. However, when the PS domain congestion occurs, the PS domain and circuit switching (CS) for initiation of a combined attached procedure or a combined routing area update procedure is performed by the MTC device or low priority device. ; Circuit-Switched) There is a situation in which a connection request can be sent to both domains. Although the CS domains of the service network may not mix, the behavior of the service network for the CS domain is indeterminate in this case. As a result, problems such as non-deterministic behavior of service networks and MTC devices or low priority devices may arise.

The present invention provides a method for congestion control for an MTC device or a low priority device and an apparatus using the same.

In one aspect of the invention, there is provided a mobile communication device configured for MTC or configured as a low priority device. The mobile communication device includes a wireless module and a controller module. The wireless module performs wireless transmission and reception for the service network. The controller module sends a connection request message through the wireless module to the service network in response to initiating the combined connection procedure or the combined routing area update procedure for both the PS and CS domains, and extends from the service network through the wireless module. A connection denied message with an indication of a pending wait timer. In addition, the controller module initiates a location registration procedure for the CS domain or enters a substate in which initiation of the location registration procedure for the CS domain is allowed in response to the access rejection message for the PS domain.

Correspondingly, a method is provided for congestion control by a mobile communication device configured for MTC or configured as a low priority device. The method includes sending a connection request message to a service network in response to initiating a combined connection procedure or a combined routing area update procedure for both the PS and CS domains, the connection having an indication of an extended wait timer from the service network. Receiving a reject message, and in response to the access rejection message for the PS domain, initiating a location registration procedure for the CS domain or entering a substate in which initiation of the location registration procedure for the CS domain is permitted; .

In another aspect of the present invention, a mobile communication device configured for MTC or configured as a low priority device is provided. The mobile communication device includes a wireless module and a controller module. The wireless module performs wireless transmission and reception for the service network. The controller module receives via the wireless module a release message for the PS domain with an indication of an extended standby timer from the service network, and the back corresponding to the extended standby timer in response to the release message for the PS domain. Start the back-off timer. In addition, the controller module does not initiate any connection establishment to the PS domain during the progression of the backoff timer.

Correspondingly, a method is provided for congestion control by a mobile communication device configured for MTC or configured as a low priority device. The method includes receiving a disconnection message for a PS domain having an indication of an extended standby timer from a service network, starting a backoff timer corresponding to the extended standby timer in response to a disconnection message for the PS domain; And initiating no connection establishment for the PS domain during the progression of the backoff timer.

In another aspect of the invention, a service network is provided. The service network includes a core network and an access network. The core network restricts any access to the PS domain from a mobile communication device configured for MTC or configured as a low priority device when detecting a system overload for the PS domain. The access network is configured for the PS domain with an indication of the extended standby timer to the mobile communication device in response to the access restriction to prohibit any access attempt by the mobile device to the PS domain for the specified period of time for the extended standby timer. Send disconnect message.

Correspondingly, a method for congestion control for an MTC device or a low priority device by a service network is provided. The method includes detecting a system overload for the PS domain and an indication of the extended standby timer at the mobile communication device to prohibit any attempted access of the mobile communication device to the PS domain for a specified period of time with respect to the extended standby timer. Limiting any access to the PS domain from the mobile communication device configured for MTC or configured as a low priority device in response to a system overload for the PS domain by sending a connection release message for the PS domain with It includes.

Other aspects and features of the present invention will become apparent to those skilled in the art upon reviewing the following description of specific embodiments of apparatus and method for congestion control for MTC devices or low priority devices.

According to the present invention, a method for congestion control for an MTC device or a low priority device and an apparatus using the same can be provided.

The invention will be understood more fully by reference to the following detailed description and examples taken in conjunction with the accompanying drawings.
1 is a block diagram illustrating a mobile communication environment according to an embodiment of the present invention.
2 is a message sequence diagram illustrating congestion control using a connection release message for an MTC device or a low priority device in accordance with an embodiment of the present invention.
3 is a message sequence diagram illustrating congestion control using an access rejection message for an MTC device or a low priority device in accordance with another embodiment of the present invention.
4 is a message sequence diagram illustrating congestion control using a connection release message for an MTC device or a low priority device in accordance with an embodiment of the present invention.
5 is a flow diagram illustrating a method for congestion control using a connection reject message for an MTC device or a low priority device in accordance with an embodiment of the present invention.
6 is a flow diagram illustrating a method for congestion control using a connection release message for an MTC device or a low priority device in accordance with an embodiment of the present invention.
7 is a flowchart illustrating a method for congestion control using a connection release message for an MTC device or a low priority device in accordance with another embodiment of the present invention.

The following description is made in the best mode for carrying out the present invention. This description is made for the purpose of illustrating the general principles of the invention and is not to be taken in a limiting sense. Note that the 3GPP specification described herein is used to teach the true meaning of the invention, and the invention is not so limited.

In order to solve the above problem, the present invention provides an apparatus and method for congestion control for an MTC device or a low priority device. 1 is a block diagram illustrating a mobile communication environment in accordance with an embodiment of the present invention. In the mobile communication environment 100, the mobile communication device 110 is configured for MTC or as a low priority device and is wirelessly connected to the service network 120 to obtain a wireless service. The service network 120 may include an access network 121 and a core network 122, which may be a universal terrestrial radio access network (UTRAN) in WCDMA technology or in LTE / LTE-A technology. It may be an Evolved-UTRAN (E-UTRAN), and the core network 122 may be a GPRS core in WCDMA technology or an Evolved Packet Core (EPC) in LTE / LTE-A technology. The mobile communication device 110 is a wireless module 111 for performing the functions of wireless transmission and reception for the service network 120, and as a wireless module 111 and a display unit and / or a man-machine interface (MMI). And a controller module 112 for controlling the operation of other functional components, such as a functioning keypad, a program unit of an application or a storage unit that stores a communication protocol. For clarity, the wireless module 111 may be a radio frequency (RF) unit, and the controller module 112 may be a micro-control unit (MCU) or general purpose processor of the baseband unit. Can be. Baseband units perform baseband signal processing, including analog to digital conversion (ADC) / digital to analog conversion (DAC), gain adjustment, modulation / demodulation, encoding / decoding, etc. It can include a number of hardware devices for. The RF unit may receive an RF radio signal and convert the received RF radio signal into a baseband signal processed by the baseband unit, or may receive a baseband signal from the baseband unit and later transmit the received baseband signal. Can be converted into an RF wireless signal. The RF unit may also include a number of hardware devices for performing radio frequency conversion. For example, the RF unit may comprise a mixer that multiplies the baseband signal with a carrier wave oscillating at the radio frequency of the mobile communication system, the radio frequency being WCDMA, depending on the Radio Access Technology (RAT) in use. It may be 900 MHz, 1900 MHz, or 2100 MHz used in the system, or 900 MHz, 2100 MHz, or 2.6 GHz used in the LTE or LTE-A system, or otherwise.

More specifically, the controller module 112 controls the wireless module 111 for PS domain congestion control. 2 is a message sequence diagram illustrating congestion control using a connection release message for an MTC device or a low priority device in accordance with an embodiment of the present invention. As shown in FIG. 2, the core network 122 first detects congestion occurrence for the PS domain of the service network 120 (step S210), and then PS domains from any MTC device and low priority device. The access network 121 is instructed to restrict access to the network (step S220). After the occurrence of PS domain congestion, the mobile communication device 110, configured for MTC or configured as a low priority device, performs a combined connection procedure or combined routing area (RA) update for both the PS and CS domains. In response to initiating the procedure, an RRC CONNECTION REQUEST message is transmitted to the service network 120 through the wireless module 111 (step S230). That is, if there is no connection between the mobile communication device 110 and the service network 120, the connection must be established before performing the combined connection procedure or the combined routing area update procedure. Upon receiving the RRC CONNECTION REQUEST message, the access network 121 is instructed to restrict access to the PS domain from any MTC device and low priority device, so the access network 121 displays an extended wait timer. Respond to the mobile communication device 110 with an RRC CONNECTION REJECT message (step S240). When the mobile communication device 110 receives the RRC CONNECTION REJECT message, the controller module 112 starts an extended wait timer (step S250). During the duration of the extended wait timer, the mobile communication device 110 does not initiate establishment of any connection to the PS domain, i.e. the mobile communication device 110 sends any connection request message to the PS domain. Note that it is prohibited. Unlike conventional mobile communication devices in accordance with the TS 23.060 and 25.331 specifications, the mobile communication device 110 may proceed to initiate a location registration procedure to obtain a CS service. In detail, the controller module 112 transmits a location update request message to the service network 120 through the wireless module 111 (step S260). Given that congestion in the PS domain does not necessarily imply congestion in the CS domain, the service network 120 may determine whether to accept the location registration request according to the system load of the CS domain. In this embodiment, the service network 120 responds to the mobile communication device 110 with a LOCATION UPDATING ACCEPT message due to the fact that the CS domain is not congested (step S270). Thus, the mobile communication device 110 can obtain the CS service as soon as possible, instead of waiting until the expired wait timer expires.

3 is a message sequence diagram illustrating congestion control using an access rejection message for an MTC device or a low priority device in accordance with another embodiment of the present invention. As in FIG. 2, the core network 122 first detects the occurrence of congestion for the PS domain of the service network 120 (step S310), and then for the PS domain from any MTC device and low priority device. The access network 121 is instructed to restrict access (step S320). After the occurrence of PS domain congestion, the mobile communication device 110 configured for MTC or configured as a low priority device initiates a combined connection procedure or a combined routing area update procedure for both the PS and CS domains. In response, the RRC CONNECTION REQUEST message is transmitted to the service network 120 through the wireless module 111 (step S330). That is, if there is no connection between the mobile communication device 110 and the service network 120, the connection must be established before performing the combined connection procedure or the combined routing area update procedure. When receiving the RRC CONNECTION REQUEST message, the access network 121 is instructed to restrict access to the PS domain from any MTC device and low priority device, so that the access network 121 is the mobile communication device 110. In response to the RRC CONNECTION REJECT message indicating the wait timer extended in step S340. When the mobile communication device 110 receives the RRC CONNECTION REJECT message, the controller module 112 starts an extended wait timer (step S350). During the duration of the extended wait timer, the mobile communication device 110 does not initiate establishment of any connection to the PS domain, i.e. the mobile communication device 110 sends any connection request message to the PS domain. Note that it is prohibited. After that, the controller module 112 enters the "MM IDLE" state ("MM" stands for "Mobility Management" according to the TS 25.331 specification, and the MM IDLE state is TS 23.060, which allows the initiation of the location registration procedure for the CS domain). Enters the "ATTEMPTING TO UPDATE" sub-state of the mobile station (MS) according to the specification, e.g., the specific operating state of the mobile communication device 110 (step S360), and operates the service mode of the service network 120 in network operation. Process as Mode (Network Mode of Operation) II or III (step S370). When staying in the "ATTEMPTING TO UPDATE" substate, the controller module 112 may initiate a location registration procedure for acquiring the CS service by sending a LOCATION UPDATING REQUEST message to the service network 120 via the wireless module 111. (Step S380). Specifically, the location registration procedure may be generated from a connection management (CM) layer of the mobile communication protocol, generated by a user request or location change of the mobile communication device 110 or in response to the expiration of a periodic timer for the location registration procedure. It may be initiated in response to the CM connection request of the. In one embodiment, the communication protocol may be implemented as program code executing on the controller module 112. In this embodiment, since the CS domain is not congested, the service network 120 responds to the mobile communication device 110 with a LOCATION UPDATING ACCEPT message (step S390). Thus, the mobile communication device 110 can acquire the CS service as soon as possible, instead of waiting until the expiration of the extended wait timer as in conventional mobile communication devices.

4 is a message sequence diagram illustrating congestion control using a connection release message for an MTC device or a low priority device in accordance with an embodiment of the present invention. Initially in this embodiment, at least a connection is established to the PS domain between the mobile communication device 110 and the service network 120. In other embodiments, there may be a first connection established for the PS domain and a second connection established for the CS domain. Later, core network 122 detects congestion occurrence for the PS domain of service network 120 (step S410), and then accesses to limit access to the PS domain from any MTC device and low priority device. Command to the network 121 (step S420). In response to the command of access restriction for the PS domain, the access network 121 sends a SIGNALLING CONNECTION RELEASE message indicating the duration for the extended wait timer and indicating the release of the connection to the PS domain. (Step S430). When the mobile communication device 110 receives the SIGNALLING CONNECTION RELEASE message, the controller module 112 releases the established connection to the PS domain (step S440) and waits extended to count the period indicated in the SIGNALLING CONNECTION RELEASE message. The backoff timer corresponding to the timer is started (step S450). Specifically, the time period is delivered to the Non-Access Stratum (NAS) layer in the mobile communication protocol, and the backoff timer is started by the NAS layer. In one embodiment, the mobile communication protocol may be implemented as program code executed by the controller module 112. During the progression of the backoff timer, the mobile communication device 110 does not initiate establishment of any connection to the PS domain, i.e., the mobile communication device 110 until GPRS Mobility Management (GMM) expires until the backoff timer expires. Note that initiating the connection is prohibited.

5 is a flow diagram illustrating a method for congestion control using a connection reject message for an MTC device or a low priority device in accordance with an embodiment of the present invention. In this embodiment, the method may be applied to any mobile communication device configured for MTC or configured as a low priority device, such as mobile communication device 110 of FIG. Initiating the method, the mobile communication device sends a connection request message to the service network in response to initiating a combined connection procedure or a combined routing area update procedure for both the PS and CS domains (step S510). In other words, in order to initiate a combined connection procedure or a combined routing area update procedure, a connection must first be established if there is no connection between the mobile communication device and the service network. Thereafter, the mobile communication device receives a connection denied message with an indication of an extended waiting timer from the service network (step S520). In this embodiment, the connection request is denied due to the fact that the PS domain of the service network is congested, and access to the PS domain from the MTC device and the low priority device should be restricted. In response to the access denied message, the mobile communication device initiates a location registration procedure for the CS domain or enters a sub state that allows the initiation of a location registration procedure for the CS domain (step S530). Specifically, the mobile communication device also starts an extended wait timer and does not initiate any connection establishment to the PS domain during the duration of the extended wait timer. In one embodiment, the mobile communication device can initiate a location registration procedure for the CS domain by sending a LOCATION UPDATING REQUEST message to the service network, and can obtain the CS service if the service network responds with a LOCATION UPDATING ACCEPT message. . In one embodiment, the substate may be the "ATTEMPTING TO UPDATE" substate of the "MM IDLE" state, and the mobile communication device is serviced as an NMO II or III in which connection establishment for the CS and PS domains can be performed separately. It can handle the mode of operation of the network. The method allows the mobile communication device to acquire the CS service as soon as possible, instead of waiting for the expiration of the extended wait timer.

6 is a flow diagram illustrating a method for congestion control using a connection release message for an MTC device or a low priority device in accordance with an embodiment of the present invention. In this embodiment, the method may be applied to any mobile communication device configured for MTC or configured as a low priority device, such as mobile communication device 110 of FIG. Starting the method, the mobile communication device receives a disconnection message for the PS domain with an indication of an extended wait timer from the service network (step S610). In one embodiment, the connection release message may be a SIGNALLING CONNECTION RELEASE message and may be sent by the service network upon detection of PS domain congestion. In response to the disconnection message for the PS domain, the mobile communication device starts an extended wait timer (step S620). Thereafter, during the progression of the extended waiting timer, the mobile communication device does not initiate any connection establishment to the PS domain (step S630).

7 is a flowchart illustrating a method for congestion control using a connection release message for an MTC device or a low priority device in accordance with another embodiment of the present invention. In this embodiment, the method may be applied to any service network such as service network 120 of FIG. 1 for congestion control of access loads from MTC devices or low priority devices. Starting the method, the service network first detects a system overload for the PS domain (step S710). In response to a system overload for the PS domain, the service network sends a disconnection message for the PS domain with an indication of the extended timer to the mobile communication device, thereby configuring the mobile device as a low priority device or configured for MTC. Restrict any access to the PS domain from the communication device, thereby prohibiting any access attempt by the mobile communication device to the PS domain for the specified period of time for the extended wait timer (step S720). In one embodiment, the connection release message may be a SIGNALLING CONNECTION RELEASE message that includes a timer information element (IE) to indicate a duration for the extended wait timer. Specifically, upon receiving the connection release message, the mobile communication device releases the established connection to the PS domain and starts a backoff timer corresponding to the wait timer extended to count the duration. Note that during the progression of the backoff timer, the mobile communication device does not initiate any connection establishment to the PS domain.

Unlike conventional disconnection messages according to the TS 23.060 and 25.331 specifications, the disconnection messages described in FIGS. 6 and 7 include a timer IE for indicating a duration for an extended wait timer, such that the mobile communication device is configured to have a PS domain. Note that the extended wait timer can be properly started to withhold connection establishment.

While the present invention has been described by way of example with respect to preferred embodiments, it is to be understood that the invention is not so limited. Those skilled in the art can make various substitutions and modifications without departing from the scope and true meaning of the invention. For example, the method for congestion control for an MTC device or a low priority device may also be applied to mobile communication devices and service networks according to any evolved technology of WCDMA / LTE / LTE-A technology. Accordingly, the scope of the invention should be defined and protected by the following claims and their equivalents.

110: mobile communication device
111: wireless module
112: controller module
120: Service network
121: access network
122: core network

Claims (8)

Low priority device configured or configured for Machine Type Communication (MTC), wherein the low priority device is delay-tolerant compared to other devices not configured as MTC or low priority device. In the mobile communication device,
A wireless module configured to perform wireless transmission and reception for a service network; And
Through the wireless module in response to initiating a combined attachment procedure or a combined routing area update procedure for both Packet-Switched (PS) and Circuit-Switched (CS) domains. Send a connection request message to the service network,
Receive, via the wireless module, an access rejection message with an indication of an extended wait timer for the PS domain from the service network,
And a controller module configured to, in response to the access denial message, initiate a location registration procedure for the CS domain or enter a substate in which initiation of a location registration procedure for the CS domain is permitted. device. The mobile communication device of claim 1, wherein the substate is a "ATTEMPTING TO UPDATE" substate of a "Mobility Management (ID)" state defined in 3GPP technical specifications. 3. The system of claim 1 or 2, wherein the controller module also initiates an extended wait timer for the PS domain in response to the access rejection message, and during the duration of the extended wait timer for the PS domain. And not initiate any connection establishment to the PS domain. The network mode of operation of claim 3, wherein the controller module is further configured to change an operation mode of the service network during a duration of an extended standby timer for the PS domain in response to entering the sub-state. NMO) II or III. 2. The system of claim 1, wherein the controller module is further configured to contact the CS domain in response to a user's request, location change of the mobile communication device, or expiration of a periodic timer for the location registration procedure when in the substate. And initiate a location registration procedure for the mobile communication device. Low priority device configured or configured for Machine Type Communication (MTC), wherein the low priority device is delay-tolerant compared to other devices not configured as MTC or low priority device. A method for congestion control by a mobile communication device,
Request access to the service network in response to initiating a combined attachment procedure or a combined routing area update procedure for both Packet-Switched (PS) and Circuit-Switched (CS) domains. Sending a message;
Receiving an access rejection message with an indication of an extended wait timer for the PS domain from the service network;
In response to the access denial message, initiating a location registration procedure for the CS domain or entering a substate in which initiation of a location registration procedure for the CS domain is permitted. 7. The congestion control method of Claim 6, wherein the substate is a "ATTEMPTING TO UPDATE" substate of a "Mobility Management (MM) IDLE" state defined in 3GPP technical specifications. 8. The method of claim 6 or 7, further comprising starting an extended wait timer for the PS domain in response to the access denied message, and making any connection to the PS domain during the duration of the extended wait timer for the PS domain. And further comprising not initiating establishment.

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